From: Sebastian Sanchez <sebastian.sanchez@intel.com>
Date: Wed, 2 May 2018 06:43:47 -0700
Subject: IB/hfi1: Create common functions for affinity CPU mask operations
Patch-mainline: v4.18-rc1
Git-commit: cf38ea100edfcc0ec0a5797966d69ec4e10fe4f1
References: bsc#1096793 FATE#325050

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 <michael.j.ruhl@intel.com>
Signed-off-by: Sebastian Sanchez <sebastian.sanchez@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/hfi1/affinity.c |   83 ++++++++++++++++++++++++----------
 1 file changed, 60 insertions(+), 23 deletions(-)

--- a/drivers/infiniband/hw/hfi1/affinity.c
+++ b/drivers/infiniband/hw/hfi1/affinity.c
@@ -77,6 +77,58 @@ static inline void init_cpu_mask_set(str
 	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)
 {
@@ -456,17 +508,12 @@ static int get_irq_affinity(struct hfi1_
 		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);
 	}
@@ -526,10 +573,7 @@ void hfi1_put_irq_affinity(struct hfi1_d
 
 	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);
@@ -640,10 +684,7 @@ int hfi1_get_proc_affinity(int node)
 	 * 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
@@ -767,11 +808,7 @@ void hfi1_put_proc_affinity(int cpu)
 		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);
 }